Machine gun



Feb. 26, 1957 w. E. LEEK ETAL MACHINE GUN 4 Sheets-Sheet 1 Filed Jan. 11, 1954 5 I IIII at II S JNVENTORS WA XNE E. L EEK CHARLES H. MORS BY CHARLES C.WEBB

4 Sheets-Sheet 2 W. E. LEEK ETAL MACHINE GUN Filed Jan. 11, 1954 Feb. 26, 1957 INVENTORS WAYNE E. LEEK CHARLES H. MORSE BY CHARLES C. WEBB Q ATTOR'ME Feb. 26, 1957 w. E. LEEK ETAL 2,782,688

MACHINE GUN Filed Jan. 11, 1954 4 ShBe'tS-ShQGt 3 F/Qq 6 V INVENTORS WAYNE E. LEEK CHARLES H. MORSE BY CHARLES C. WEBB ATTORNEY Feb. 26, 1957 w. E. LEEK EIAL 2,782,683

MACHINE GUN Filed Jan. 11, 1954 4 Sheets-Sheet 4 INVENTORS WAYNE 5. LEEK CHARLES H.Mo E 2 BY CHARLES c. WE

ATTOHN fixed abutment 12 in the feed compartment.

United States Patent '0 l MACHINE "GUN Wayne E. Leek, Ilion, Charles H. .Mors'e Herkimer, and

Charles C. Webb, Mohawk, N. Y., asslgnors to Remington Arms Company, Inc., Bridgeport, Conm, a-cor- 'por'ati'on of Delaware Application-January 11,1954, Serial No. 403,278 7 Claims. (61.89-199) This invention relates to a machine gun particularly adapted for military usage in restricted locations such as in armored vehicles.

A particular object of this invention is to provide a machine gun which can be field-stripped or disassembled to the extent necessary for routine inspection, cleaning and/ or barrel interchange without resulting in any loose parts to handle, springs to escape, etc. Another object is to make it possible to interchange barrels without deranging the belt feed mechanism and without handling a hot barrel or having to dispose of such a barrel within the confines of an armored vehicle orother enclosure. 'The exact nature of the invention as Well as other objects and advantages thereof will more fully appear from consideration of the following specification referring to the attached drawings in which:

Fig. 1 is a longitudinal sectional view through :amachine gun embodying our invention.

Fig. 2 is a side elevational view of the same machine gun.

Fig. 3 is a rear end elevational view.

Fig. 4 is a partial cross-sectional view on the line 4--4 of Figs. 1 and 6.

'Fig. 5 is a partial cross-sectional view on the line 55 cf Fig. 1.

Fig. 6 is a partial horizontal sectional view on theline 6-6 of Figs. 2 and 5.

Fig. 7 is a partial cross-sectional view on the line 7-7 of Fig. 1.

Fig. 8 is a longitudinal sectional view through a modified barrel and barrel extension assembly.

Referring to the drawings by characters of reference, it can be seen that there is shown a recoil operated machine gun comprising a barrel 1 longitudinally slidable in a jacket 2 and front barrel bushing 3. The barrel is v I secured, by means to be later discussed 1n more detail,

to a barrel extension 4, which provides rear end support for the barrel and is itself longitudinally slidable in a receiver 5. V

The top opening into the receiver is partially closed by a top plate 6 and by a crossbar '7, both riveted, brazed, or otherwise secured in place. Over this area there is secured a feed compartment 8. Within this feed compartment there is mounted for fore and aft sliding movement a feed slide 9 from which there depends a lug l0 engaging the barrel extension 4. The feed slide and the lug 10 are urged forwardly by a spring 11 engaging a Thus, the 'recoilingbarrel acts to driv'e'the feed slide rearwardly and the spring acts to'return both feed slide and barrel.

Although the feed slide is driven directly from the barrel, the operation of the cartridge feed is otherwise conventional. A reversible feed cam plate 13 is provided with a cam track engaging a post 14 projecting upwardly from a transversely slidable feed pawl block 14a. The feed pawls and holding pawls for handling the pushthr'ough type of disintegrating link belt are conventional. The receiver "5 "is closed at the rear end by a boir-lik'e 2,782,688 Patented Feb. 26, 1957 closure which defines a boltcompartment 1 5. Interiorly, the bolt compartmentissimply a rearward continuation of the receiver and together they form a housing within which the bolt 16 is guidedtfor longitudinal sliding movement. A bolt'return spring may conveniently bein two sections 17 and 18 separated by a spacer 19 slidable on a spring pilot 20. With the bolt in its reannost position. the two sections .of the spring, the spacer, and the pilot are almost completely housed within the bolt body and the bolt is itself completely within the bolt compartment 15. This-machine .gun is one which fires from an open bolt and it will ordinarily remain after firing has ceased with the bolt in this rearmost position and engaged by the sear 21. For safelylocking the bolt, a safety plunger 22 isprovided in-thereceiver and can be pressed into the receiver to engage in front of the forward end of one of the rails 23 on-the'bolt body, as shown in Fig. 4.

Obviously, with the bolt so locked within the receiver, the bolt compartment could be completely removedfrom the receiver without exposing to dirt any of the bolt mechanismand without having any loose springs or other small parts to contend with. This disassembly is, however, :furtherfacilitated by ahinged mounting of the bolt compartment to the receiver compartment so that itmay be :swung either to the right or left, as indicated by the dotted lines in Fig. 3. Both lower corners of the receiver and of the bolt compartment are bored longitudinally and a hollow hinge bolt 24 may be inserted from the rear extended forward into a matching bore in the receiver where it may be retained by the engagement'of a snap ring fastener 25 between a receiver cut 25:: and a circumferential groove in the hollow hinge 'bolt 24. The arrangement at both lower corners of the receiver is identical and the hinge bolt may be used interchangeably at either corner to provide for swinging the bolt compartment laterally in the direction where the most free space is available. This is an important consideration in a gun designed for use in such cramped quarters as are afforded in an armored vehicle.

With the receiver and bolt compartment in alignment, the longitudinal loads are taken by interlocking the bottom surfaces at 26 and by means of a book 27 engaging the receiver bridge 7, thus making it unnecessary for the hinge bolt to absorb these loads.

The bolt compartment may be latched in alignment with the receiver by means of a locking plunger 28 springurged to project rearwardly from the longitudinal bore in the receiver which is not used for the hollow hinge bolt and, like the hinge bolt, capable of interchange. The locking plunger engages in the matching bore in the bolt compartment to hold the two members in alignment. The locking plunger may be released by means of an unlocking plunger 29 housed in the bore in the bolt compartment which can be pressed forward to move the locking plunger far enough to bring its end face into alignment with the joint between bolt compartment and receiver. A spring retainer 28a serves to limit movement of the plunger 23 in the longitudinal bore in the receiver.

With the bolt compartment swung to one side as discussed above, the bolt may be removed by applying a screw driver to the slotted end of the spring pilot 20 and pushing it forwa'r d into the bolt far enough topermit turning the locking key 20a into a groove 16a in the bolt 16, efiecting a bayonet joint type of lock and confining the springs 17 and 18 within the bolt. Release of the sear 21 and safety plunger 22 permits complete removal of the bolt without difficulty due to loose springs and the like.

To charge the gun, we make useof a charging lanyard 30 which passes forward through the hollow hinge bolt 24 intoa continuing bore in the receiver where the lanyard is joined to a'plunger 31 which is spring urged to a 33 into the receiver where it may engage with a cut 34 in the barrel extension. By pulling rearwardly on the lanyard, the barrel may be retracted against the urging of the spring 11 about 1 /2" to operate the belt feed mechanism and during this movement the barrel sear 35 drops into position to engage a shoulder 36 when the barrel returns forward to temporarily retain the barrel in a position about /2" to the rear of its forward or battery position. Just after the barrel sear drops into its active position, the charging pawl 32 pulls by the barrel release button 37 which disengages the pawl from the barrel extension, permitting the barrel and barrel extension to spring forward and stop against the shoulder 36. Atthis point in the operating cycle, the bolt, as will be later explained in more detail, has started to separate from the barrel extension and as soon as the pawl 32 has cleared the release button 37, the pawl snaps back into the receiver and engages with the corner 38 on the bolt body. A further pull on the lanyard will retract the bolt into the bolt compartment where it may be retained by the scar and by the safety plunger.

When the gun is fired by releasing the sear 21, the bolt springs forward toward the barrel extension and in a known manner the ejector 39 strips a cartridge from the push-through belt link and advances it to the chamber in the barrel. As is best shown by Figs. 1 and 6, the barrel extension 4 is formed to define two rearwardly extending side pieces 40 provided with opposed, spaced locking lugs 41. The head portion 42 of the bolt 16 is adapted to enter between the side pieces of the barrel extension and is provided with a pair of parallel sided cuts 43 in its side faces which receive a pair of locking bars 44 and 45, each of which is provided with locking lugs 46 adapted to engage in front of the lugs 41 when the locking bars are raised to their highest position relative to the bolt.

During the initial part of the firing movement of the bolt, the barrel is held about /2 to the rear of its battery position by the barrel sear 35 and the tail 47 on this sear is positioned for engagement by the forward end of the bolt to disengage the barrel sear from the shoulder 36 in the receiver. During the remaining portion of forward movement, the barrel and bolt move forward together and near the limit of forward movement cam surfaces 48 in the receiver engage the lower end of the locking bars to raise them into position in which the lugs 46 are in front of the lugs 41 and the breech is locked.

Firing is accomplished after completion of breech locking when a transversely movable plunger sear 49 engages a fixed cam (not shown) in the receiver to move the sear out of engagement with and permit firing movement of a firing pin 50 in a known manner.

After firing, the barrel and breech bolt recoil'rearwtardly locked together until cams 51 in the receiver urge the locking bars downward, moving lugs 46 out of position in front of lugs 41 while the barrel sear springs into active position ready to engage the shoulder 36. The barrel, however, continues rearwardly for about another inch to complete the operation of the feed mechanism and then returns into engagement with the shoulder 36. During this last stage of recoil movement, the barrel also acts to accelerate the bolt rearwardly. Acceleration is accomplished much as it is in the well-known Browning machine gun, although the accelerating elements are differently mounted. In our case, the accelerators 52 are pivotally mounted on the breech bolt and during the initial breech bolt unlocking stage of recoil movement extend downwardly through holes 53 in the receiver bottom. At the time unlocking is complete, the accelerator impinges on the rear edge of the holes in the receiver and commences to rotate about its pivot on the bolt in a counter-clockwise direction. During this movement, however, the barrel extension which is still recoiling with the barrel rests against the forward curved edge of the accelerators and Swingably mounted in the plunger 31 is a pawl 32 which projects through a slot the bolt, by virtue of the changing ratio in the lever system constituted by the accelerators, is forced to move rearwardly at a materially greater rate than the barrel extension. During the remaining movement of the bolt, the cartridge is extracted from the chamber and ejected through the ejection port 54 when the ejector 39 is stopped by engagement with the bolt compartment. Cooking is accomplished as in the Browning gun by a cocking lever mounted in the bolt and acting directly on the firing pin, an operating end of the cocking lever engaging the receiver.

Impact of the bolt against the rear wall of the bolt compartment is absorbed by a friction buifer comprising a plunger 55 formed with a wedged end received between a pair of spring backed split cylinder friction blocks 56.

As long as the sear is held out of engagement with the bolt and the ammunition supply holds out, automatic firing will continue. Firing may be terminated at any time by releasing the sear which will re-engage and hold the bolt at the end of the next recoil movement of the bolt.

Replacement of an overheated barrel is effected by swinging the bolt compartment with the bolt secured therein to one side, as previously discussed. Manual operation of the barrel release lever 57 will depress the plunger 58 which engages the barrel locking bars 59 (see Fig. 7) and disengages them from the groove 60 in the barrel. With the barrel locking bars thus released, a new barrel may be inserted from the rear of the receiver, pushing the Worn-out or overheated barrel out through the front end of the barrel jacket 2. It should be noted that clearance cuts 61 are provided in the receiver side walls only opposite the position occupied by the barrel locking bars when the barrel is held in its fully recoiled position by the barrel sear. There is, therefore, no possibility that the barrel could be accidentally unlatched at the instant of firing. It will be noted that these locking bars have very substantial engagement in a close-fitting slot in the barrel extension and in the barrel groove 60. Obviously, the barrel can be displaced in the barrel extension only by unlocking in the intended Way or by shearing the full crosssection of the locking bars which can readily be designed to have greater shear strength than the threaded joint commonly used to secure a barrel to receiver or barrel extension.

Should it be desired merely to remove a barrel for inspection and/ or cleaning, the barrel release button 37 may be moved upward to an inoperative position and the charging lanyard 30 pulled rearwardly. With the release button 37 out of the way, the pawl 32 remains in engagement with the cut 34 in the barrel extension and the assembly may be withdrawn by the charging lanyard far enough to permit the barrel extension to be readily grasped for complete removal. The barrel and barrel extension come out as an assembly and may, if desired, be disassembled after removal by releasing the barrel locking bars.

Fig. 8 shows an alternative barrel assembly comprising a barrel extension 62 having formed integrally therewith the chamber portion of a barrel. To this barrel extension there is threadably secured a simple cylindrical barrel 63, the joint between the barrel and barrel extension intersecting the bore in a location which will be spanned by a portion of the neck of the cartridge case. A spring detent 64 on the barrel engages notches 65 on the barrel extension to retain the assembly and, of course, the threads are so pitched that the reaction to the rotation of the projectiles by the rifting tends to tighten the joint. By this arrangement the barrel can be made with great economy, chambering and qualification of threads being two ordinarilyexpensive operations which are eliminated. With this arrangement, it is necessary to completely withdraw the assembly of barrel and barrel extension as described above before a new barrel can be inserted. I

Although we have illustrated and described a preferred embodiment of our invention in considerable detail, we

arsaese believe it will be obvious that equivalent arrangements are possible. We note, for example, that our receiver bolt compartment combination would be equally useful with blowback operated arms and with certain gas operated arrangements. Similarly, our arrangement for replacing barrels is not necessarily limited to a recoil operated type of arm. We consider to be a part of our invention all such equivalent arrangements coming within the terms of the claims appended hereto.

We claim:

1. In a machine gun having a barrel and a spring-urged breech bolt reciprocable between positions locked to said barrel for firing and remote therefrom for extraction and reloading, the combination comprising a box-like receiver into which said barrel extends and into which said breech bolt reciprocates to lock to said barrel, a box-like bolt compartment releasably secured to said receiver to form a longitudinal rearward extension of said receiver, within which the reciprocation of said breech bolt is completed, said bolt compartment being of adequate length to receive and completely house the breech bolt and spring mechanism associated therewith when said breech bolt is in said position remote from the barrel, and means to releasably retain said breech bolt in said remote position completely enclosed in said bolt compartment, said receiver and said bolt compartment being joined to each other by means including a hinge bolt mounted parallel to the axis of the bore of the barrel in one of the longitudinal corners of the bolt compartment and extending therefrom into secured relation in an aligned bore in one of the longitudinal corners of said receiver, said hinge bolt forming a journal about which said bolt compartment can be rotated to swing said bolt compartment and the breech bolt contained therein to one side out of opposition to the open rear end of the box-like receiver.

2. The combination described in claim 1, an opposite longitudinal corner of said receiver and of said bolt compartment being provided with interengaging reciprocating latch means to releasably secure said bolt compartment in longitudinal extension of said receiver, said hinge means and said latch means being mounted in substantially identical longitudinal bores in opposed longitudinal corners of said receiver and bolt compartment, said hinge and latch means being capable of being interchanged to permit said bolt compartment to be swung laterally to a desired side.

3. The combination described in claim 1, said receiver and bolt compartment being provided with hooked, interengaging means which interlock to resist longitudinal separation of said bolt compartment and receiver only when the bolt compartment has been rotated about said hinge pin into position as a longitudinal rearward extension of the receiver.

4. The combination described in claim 1, said receiver including a barrel extension and barrel supporting means formed thereon to permit removal and replacement of the barrel when the open rear end of the receiver has been completely exposed by swinging said bolt compartment laterally to one side about the axis of the hinge pm.

5. The combination described in claim 4, said barrel extension being provided with a longitudinal bore through which the barrel may pass and with releasable latch means .engageable with the barrel to releasably secure the barrel to said barrel extension, release of said latch means permitting the barrel to be pushed forward out of the receiver by the insertion from the rear of a replacement barrel.

6. The combination described in claim 4, said barrel extension being formed to define a cartridge receiving chamber embracing the body and all but a short portion of the neck of a cartridge case, said barrel being throated to receive the remainder of the neck of a cartridge case and a bullet loaded therein.

7. The combination described in claim 5, said latch means being so mounted on the barrel extension as to engage the inner wall of the receiver and be prevented thereby from being released from the barrel when said barrel is in firing position, said barrel extension, latch means, and barrel being capable of at least limited movement in. said receiver to a position in which said latch means can be released from said barrel.

References Cited in the file ofthis patent UNITED STATES PATENTS 729,413 Reifgraber May 26, 1903 874,856 Mason Dec. 24, 1907 1,402,459, Swebilius Jan. 3, 1922 1,755,034 Stange Apr. 15, 1930 FOREIGN PATENTS 234,998 Germany May 27, 1911 562,476 Germany Oct. 26, 1932 496,452 Belgium Oct. 16, 1950 

